CODING INTERNATIONAL CO LTD

NXP Semiconductors N.V. announced enhancements to its family of Class-AB audio amplifiers, providing improved quiescent current reduction and decreased smart phone signal interference. The integrated GSM input filtering is built in for increased EMC robustness. Building on NXP’s expertise in Best Efficiency Mode audio applications, the TDF8546A (4x 25Watt) and TDF8548A (4x 28Watt) are also the industry’s first Class-AB amplifiers to extend line driver detection to 1kOhm load impedance.

As smartphone connectivity becomes increasingly central to automotive infotainment applications, the industry has to ensure that audio quality is not compromised by smartphone signal interference. Designed specifically for automotive applications, NXP’s Class-AB audio amplifiers provide increased GSM robustness to mitigate the influence of smartphones on loud speakers, responding to OEMs’ demand for a cost-effective solution that improves sound quality.

The TDF8546, TDF8546A and TDF8548A amplifiers are quad-channel Class-AB amplifiers available with NXP’s ground-breaking Best Efficiency Mode operating as low as 6V, reducing power dissipation by 17% compared to other high-efficiency solutions in its class. Both amplifiers enable a seamless audio experience during sudden supply voltage drops in hybrid electric vehicles and other cars using start-stop systems.

The enhancement of NXP’s family of Class-AB audio amplifiers further supports NXP’s vision of connecting the car. From telematics and car-to-x communications to smarter infotainment systems, NXP is supplying the chips making the connected car a reality.

In-car use of smart devices has become common over the past few years, but the potential interference they generate creates a major headache for audio OEMs aiming to provide excellent sound performance. These new amplifiers significantly reduce the effect that smart device signals can have on the speaker cable, while delivering superior sound performance. Features:

• 4 x 25W (TDF8546A) output power (14.4V, 10% THD, 4 Ω)
• 4 x 28W (TDF8548A) output power (14.4V, 10% THD, 4 Ω)
• Operating supply voltage from 6 to 18V
• Excellent sound performance – no pop noise; suitable for 2 Ω to 4 Ω speakers
• Best Efficiency Mode – low quiescent current per channel
• Power dissipation reduced by 17% compared to other high-efficiency Class-AB amplifiers
• Power dissipation reduced by 35% compared to standard Class-AB amplifiers
• No switch noise due to ‘soft switching’
• Protection against short thermal overload and ESD (Electrostatic Discharge)
• I²C bus diagnostics, including start-up diagnostics, clip detection and pre-warning
• Small footprint: HSOP36 and DBS27 packages